Catching mechanisms for tubular septal occluder

ABSTRACT

A septal occluder, such as one made from a polymer tube, can have portions on either side of a patent foramen ovale (PFO) or other septal defect. The portions on either side can be held in place with a catching mechanism that can take one of many forms. The tube can be made of bioresorbable materials.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 13/591,070 filed Aug. 21, 2012, now issued as U.S. Pat. No.8,480,709; which is a continuation application of U.S. application Ser.No. 11/121,833 filed May 4, 2005, now issued as U.S. Pat. No. 8,257,389;which claims the benefit under USC §119(e) to U.S. Application Ser. No.60/569,422 filed May 7, 2004. The disclosure of each of the priorapplications is considered part of and is incorporated by reference inthe disclosure of this application.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates generally to an occlusion device for theclosure of physical anomalies like septal apertures, such as patentforamen ovale and other septal and vascular defects.

Background Information

A patent foramen ovale (PFO), illustrated in FIG. 1, is a persistent,one-way, usually flap-like opening in the wall between the right atrium11 and left atrium 13 of the heart 10. Because left atrial (LA) pressureis normally higher than right atrial (RA) pressure, the flap usuallystays closed. Under certain conditions, however, right atrial pressurecan exceed left atrial pressure, creating the possibility that bloodcould pass from the right atrium 11 to the left atrium 13 and bloodclots could enter the systemic circulation. It is desirable that thiscircumstance be eliminated.

The foramen ovale serves a desired purpose when a fetus is gestating inutero. Because blood is oxygenated through the umbilical chord, and notthrough the developing lungs, the circulatory system of a heart in afetus allows the blood to flow through the foramen ovale as aphysiologic conduit for right-to-left shunting. After birth, with theestablishment of pulmonary circulation, the increased left atrial bloodflow and pressure results in functional closure of the foramen ovale.This functional closure is subsequently followed by anatomical closureof the two over-lapping layers of tissue: septum primum 14 and septumsecundum 16. However, a PFO has been shown to persist in a number ofadults.

SUMMARY OF THE INVENTION

This description discloses several techniques for catching or locking animplant in a desired shape. This technique relates particularly to, butis not limited to, a septal occluder made from a polymer tube. Thesetechniques, in addition to use with septal occluders, could be appliedto other medical devices, such as other expandable devices constructedfrom an underlying tubular structure. Features and advantages willbecome apparent from the following detailed description, drawings, andclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a shows a cross sectional diagram of a human heart with a PFO.

FIGS. 1b and 1c show one type of occluder that may be used with thecatching mechanisms herein.

FIGS. 2a through 2j show several variations of an internal interfacecatching mechanism having a split tube and barbs for engaging occluderjoints.

FIG. 3 shows a catching mechanism with hooked ends made from shapememory metal.

FIGS. 4 and 5 show an internal interface catching mechanism with acone-shaped catching end.

FIGS. 6a and 6b show a threaded catching mechanism.

FIG. 7 shows a tie-wrap type catching mechanism.

FIG. 8 through 15 show several views of a ball and string catchingmechanism.

FIGS. 16 through 19 show an occluder with a staggered barb catchingmechanism.

FIGS. 20 through 22 show an occluder with an arrowhead catchingmechanism.

FIG. 23 through 25 show an internal interference catching mechanismhaving one or more nail-head shaped catch stops.

FIG. 26 through 29 show an occluder with a ratchet-type catchingmechanism.

FIGS. 30 and 31 show a catching mechanism having a split/protrusioncatch stop for engaging an Occluder joint.

FIGS. 32 and 33 show a spring release catching mechanism.

FIGS. 34 through 37 illustrate two examples of an external interferencecatching mechanism.

FIGS. 38 through 42 show examples of a stick anchor catching mechanism.

FIGS. 43 through 51 show several examples of a puzzle catchingmechanism.

FIGS. 52 through 55 show several examples of a catching mechanism thatis part of the occlusion member.

FIGS. 56 through 61 show several examples of a “two elements” catchingmechanism.

FIGS. 62 and 63 illustrate an example of a coil catching mechanism.

FIGS. 64 through 66 show a catching mechanism with an end cap catchstop.

FIGS. 67 and 68 show a “twist-tie” catching mechanism.

FIGS. 69 and 70 show an example of a double anchor catching mechanism.

DETAILED DESCRIPTION OF THE INVENTION

The described embodiments are catching mechanisms for securing a septaloccluder in an expanded, deployed configuration. This description setsforth a number of catching mechanisms, many of which can be grouped forconvenience (and not in a limiting manner) based on a particularcharacteristic or set of characteristics as follows:

I) Internal Interference Catches: include a catching member disposedinside of a joint of the implant. The catching member has aninterference feature such that one piece engages a joint to impedemovement with respect to that joint.

II) External Interference Catches: include a catching member disposedoutside of a joint of the implant. The catching member has aninterference feature that engages the joint to impede movement withrespect to the joint.

III) Stick Anchor Catches: include a stick portion that rotates withrespect to the longitudinal axis of the occluder. When the stick issubstantially parallel to the longitudinal axis, the stick can passrelatively unimpeded through an occluder joint. When the stick rotatesto be substantially perpendicular to the longitudinal axis, the stickcannot pass through the joint because the length of the stick is largerthan the inside diameter of the joint.

IV) “Puzzle” Catches: include catching members of various shapes thatmate in the caught position, similar to pieces of a conventional puzzle.

V) Catch Within the Occlusion Member: includes adhesive or othersecuring material as part of the occluder structure.

VI) Two Elements Catch and Coil Catch: two elements that operate on theprinciple that two elements work together such that either one is smallenough to pass through an occluder joint, but the two elements togetherform a unit that is too big to pass through the occluder joint.

VII) End Cap Catch: includes an end cap that fixedly attaches to one orboth ends of the occluder and engages a catching member to hold theoccluder in a caught, deployed position.

VIII) Miscellaneous Catches: includes catches that do not fall in theprevious seven categories.

Each of these groups is described in more detail below.

The embodiments in the first group are called internal interferencecatches. They include catching members that pass through a center jointof an implant along a longitudinal axis. This type of catching memberhas a section or sections with a larger outside diameter (OD) than theinside diameter (ID) of the implant, so the catching member can engagethe implant in one of several ways, such as: (a) the section of thecatching member with a larger OD compresses during the catching processas the catching member passes through the implant, and/or (b) theimplant ID increases during the catching process as the catching memberpasses through the implant. In either case, a proximal tip of thecatching member passes through the implant device, the dimensions ofboth the device and the implant return to more or less their originalstate, thereby “catching” the implant. Another option is that thecatching member or part of the implant can deform temporarily to allowthe catching member to pass through.

FIG. 1b illustrates one type of septal occluder that may be caught usingcatching mechanisms described herein. In this case, an occluder 20 in adeployed position has a distal (left atrial) side 22 and a proximal side24, each with four petals. The catching mechanism 30 has a distal ball32, a proximal ball 34, and a rod 36 connecting balls 32 and 34. Balls32, 34 and rod 36 can each have a central bore (not shown) to allowcatching mechanism 30 to be delivered with occluder 20 over a guidewire. Other types of occluders, for example, those with petals havingsolid or mesh surfaces, or those with tissue scaffolds may also be used.

FIG. 1c is a side view showing occluder 20 with left atrial side 22 anda right atrial side 24, each in contact with septum secundum 16 andseptum primum 14. In this figure, the catching mechanism is shown with adelivery wire 40 and sheath 42 in a connected position before thedelivery wire 40 would be detached from ball 34.

The embodiment described in conjunction with FIGS. 1b and 1c has somesimilarities to disclosure in U.S. Patent Application No. 60/486,992,entitled Tubular Patent Foramen Ovale (PFO) Closure Device with CatchingMechanism, filed on Jul. 14, 2003, and U.S. Patent Application No.60/549,741, entitled Delivery/Recovery System for Clover Leaf SeptalOccluder, filed on Mar. 3, 2004, both of which are incorporated hereinin their entirety by reference. These incorporated documents describehow a device can be formed by making cuts or slits in a tube andcompressing the ends, and how to deliver such a device.

FIGS. 2a through 2f show embodiments of an internal interferencecatching member 100 having a longitudinal split 102 and anchor barbs 104for engaging an occluder joint. In all six of these embodiments, thecatching member 100 is fixedly attached at one end to one of theoccluder joints (either the proximal joint 106, the center joint 108, orthe distal joint 110). In other embodiments, the catching member mayinclude multiple longitudinal splits with multiple barbs. For example, apair of longitudinal splits can be used to produce four barbs. Othersplit/barb combinations may also be used.

In FIG. 2a , the occluder includes a first catching member 100 a fixedlyattached to the proximal joint 106, and a second catching member 100 bfixedly attached to the center joint 108. FIG. 2a shows the occluder inan open, released configuration. In order to catch the occluder, thebarbs 104 of the first catching member 100 a pass through and engage thecenter joint 108, and the barbs 104 of the second catching member 100 bpass through and engage the distal joint 110. Note that the barbs 104for the first catching member are oriented in a manner that is offset,and preferably orthogonal, with respect to the barbs 104 for the secondcatching member 100 b to allow the barbs 104 of the first catchingmember 100 a to pass through the longitudinal slot in the secondcatching member 100 b when the barbs 104 of the first catching memberengage the center joint 108. To allow the barbs on catching members 102b to be pushed through distal joint 110, the delivery system may need toinclude a releasable connection or movable stop for coupling to orcontact with distal joint 110 and/or center joint 108 to hold them inplace as the respective catching members are pushed through. An exampleof such a stop is shown in the incorporated application related todelivery, in which a wire extends along the axis of the device and isbent at the end in a hook. If this is not practicable, the device can be“turned around” in a configuration similar to that shown in FIG. 2dbelow.

FIG. 2b shows a perspective view of an occluder of the general typeshown in FIG. 1b with a first catching member 100 a fixedly attached tothe proximal joint 106, and a second catching member 100 b fixedlyattached to the distal joint 110. When caught, the barbs 104 of thefirst catching member 100 a and the second catching member 100 b bothengage the center joint 108.

In FIG. 2c , the occluder includes a first catching member 100 a and asecond catching member 100 b, both fixedly attached to the center joint108. When caught, the barbs 104 of the first and second catching members100 a, 100 b pass through and engage the center joint 108.

In FIG. 2d , which can be essentially a mirror image of FIG. 2a , theoccluder includes a first catching member 100 a fixedly attached to thecenter joint 108, and a second catching member 100 b fixedly attached tothe distal joint 110. When caught, the barbs 104 of the first catchingmember 100 a pass through and engage the proximal joint 106, and thesecond catching member 100 b pass through and engage the center joint108. As with FIGS. 2a, 2b, and 2c , note the offset relationship,preferably orthogonal, between the barbs 104 of the first catchingmember 100 a and the barbs 104 of the second catching member 100 b.

In FIG. 2e , the occluder includes a first catching member 100 a fixedlyattached to the proximal joint 106. When caught, the barbs 104 of thefirst catching member 100 a pass through the center joint 108 and thedistal joint 110, and engage the distal joint 110. FIG. 2e shows thefirst catching member 100 a with a split running only partially alongthe longitudinal length of the catching member. In all of theembodiments shown in FIGS. 2a through 2f , the split in the catchingmember may run along the entire length of the catching member, or onlyalong a portion of its length.

In FIGS. 2f and 2g , the occluder includes a first catching member 100 afixedly attached to the distal joint 110. The device can be caught bypulling on a delivery wire 105 that is releasably connected to joint 110or the catching member 100, while holding joint 106, for example, with adelivery catheter (not shown). The barbs 104 of the first catchingmember 100 a pass through the center joint 108 and the proximal joint106, and engage the proximal joint 106. FIG. 2g shows the occluder inthe closed and caught position. In this case unlike some otherembodiments, there is one set of barbs.

In some cases, the operator may determine that the occluder was notpositioned properly, or needs to be removed for some other reason.Techniques can be used for catching and releasing the various catchingmechanism embodiments herein. FIG. 2h shows one way to release theoccluder of the type shown in FIG. 2f . A hollow tube 111 with a bevel112 along the inside diameter at the distal tip of the tube 111 isapplied to the barbs 104 of the catching member 100 a as shown. Thebevel 112 applies pressure to the barbs 104 so as to drive them togethertowards the longitudinal center axis of the catching member 100 a, untilthe outside diameter of the barbs is smaller than the inside diameter ofthe proximal joint 106. When this occurs, the barbs 104 can pass backthrough the proximal joint 106, thereby releasing the occluder. Thedevice is therefore released from the same direction from which it isdelivered.

FIGS. 2i and 2j show perspective views of alternative embodiments of thecatching mechanism of the type described in conjunction with FIG. 2a .The catching mechanism of FIGS. 2i and 2j includes a third catchingmember with a third barb, and additional ones could be added if desired.

FIG. 3 shows a catching mechanism 114 including a shape memory material(e.g., nitinol wire) that is designed to form hooked ends 116 whendeployed in a caught position. The distal ends 118 of the catchingmechanism 114 are fixedly attached to the distal joint 110. Whiledeploying the occluder, the catching mechanism 114 has parallel proximalends in its martensite form. Once the occluder is fully deployed, theproximal ends of the catching mechanism 114 pass through the proximaljoint 106 and revert to austenite in the body to form the hooked ends116 and engage the proximal joint 106. Note that the orientation of thisembodiment may also be reversed, i.e., the hooked ends of the catchingmechanism may be on the distal end, rather than the proximal end, withthe proximal end of the catching mechanism fixedly attached to theproximal joint.

FIGS. 4 and 5 illustrate two alternate forms of an internal interferencecatch, namely, a ball catch 120 and a conical catch 122. FIG. 4 showsthe occluder in an released position, and FIG. 5 shows the occluder in acaught position. To deploy the occluder, the conical catch 122 is forcedthrough the center joint 108 and then through the proximal joint 106.The smaller outer diameter near the proximal end of the conical catch122 facilitates passage through the center joint 108 and the proximaljoint 106, but once through a center joint, the larger outside diameterof the distal end of the conical catch 122 impedes passage back throughthe center joint.

FIGS. 6a and 6b show a threaded catching mechanism that mates withmutual threads on the inside diameter of the center joint. A threadedbolt 124 extends toward the distal joint 110 from the proximal joint.The bolt is turned, such as with a slot in the head, to cause the boltto mate with a threaded opening in the distal joint. As with theembodiment in FIG. 2a , it may be desirable to have a releasableconnection or a stop to distal joint 110 to hold it in place. A wirewith a hook or barb could extend down a bore (not shown) along thelongitudinal axis of the bolt 124, and have a bend at the end whenextending through the bore to serve as a hooking stop; it would bepulled back after the device is caught. In other embodiments, a bolt canhave its head at the distal end, and a threaded collar can be formedwithin the proximal joint 106. In still other embodiments, a devicesimilar to that shown in FIG. 6a can have threads over a greater lengthsuch that the bolt can be screwed until joints 106 and 108 are closetogether or in contact and the bolt starts to engage threads at thedistal joint 110.

FIG. 7 shows a catching mechanism that engages a center joint via abarb/ridged-surface interface (similar to a “tie wrap”). FIG. 7 showsthe barb 127 on the inside wall of the center joint, and the ridges 129on the catching mechanism. In other embodiments, this orientation may beswitched.

An internal interference catching mechanism may utilize a combination oftwo or more of the mechanisms shown in FIGS. 2 through 7.

FIG. 8 shows an occluder with a ball and string catching mechanism. Inthe extended configuration for delivery (shown in FIG. 8 within adelivery sheath 136), the distal ball 130 engages the distal joint 110,and the proximal ball 132 is disposed along the delivery string 134between the distal joint 110 and the center joint 108. FIGS. 9 through12 show the delivery sequence for the ball and string catching mechanismof FIG. 8. A shown in FIG. 9, the distal portion of the occluder isdeployed from the delivery sheath 136 on the left atrial side of thePFO. FIG. 10 shows the proximal ball 132 pulled through the center joint108, thereby catching the distal portion of the occluder. FIG. 11 showsthe proximal portion of the occluder deployed from the delivery sheath136 on the right atrial side of the PFO. FIG. 12 shows the proximal ball132 pulled through the proximal joint 106, thereby catching the proximalportion of the occluder. Detaching wire 134 from ball 132 is the stepremaining to complete the delivery of the occluder in the PFO.

FIGS. 13 through 15 show a recovery sequence for removing an occluder,such as that delivered in the manner shown in FIGS. 9 through 12. FIG.13 shows the delivery sheath 126 disposed against the proximal end ofthe occluder. Wire 134 has been pulled with sufficient force to pullball 130 through the distal joint 110 thereby allowing the distal sideof the occluder to start to return toward a tubular shape. FIG. 14 showsthe distal ball 130 further pulled through the center joint 108, and upagainst the proximal joint 106, so the right atrial side starts to loseits compressive force. FIG. 15 shows the released occluder after it hasbeen retracted back into the delivery sheath and out of the PFO byadvancing the sheath, retracting the device, or some combination ofthese motions. Another method for recovering the device is using amethod similar to that shown in provisional application No. 60/569,203,filed May 7, 2004, which is incorporated herein by reference. In thatmethod, a set of claws is used to grip and pull the device, startingwith the proximal joint.

FIGS. 16 through 19 show an occluder with a staggered barb catchingmechanism. This embodiment uses a pair of barbs, either one of which canpass relatively unimpeded through a center joint. When the two barbs arealigned along the longitudinal axis (i.e., no longer staggered), theyform a catching mechanism with a combined outside diameter that isgreater than the inside diameter of the center joint, so as to impedepassage through the center joint.

FIG. 16 shows another embodiment that includes a first catching member140 with a first barb 142, a second catching member 144 with a secondbarb 146, and a distal stop 147. The first catching member 140 isfixedly attached at its distal end to an end cap 148. The secondcatching member 144 passes through the end cap 148 so that the secondcatching member 144 can slide longitudinally through the end cap 148.The first barb 142 and the second barb 146 are attached to one anotherwith a delivery string 150 (or delivery shaft, or other similar deliverymechanism), and are longitudinally staggered as shown. A delivery wire151 is shown with a releasable connection 153, which can be a ball witha set of grappling hooks. The ball is also rigidly connected to string150.

To deploy an occluder with such a staggered barb catching mechanism, theoperator pulls the delivery string so that the proximal side 157 of thedevice stops against the delivery sheath 152 as shown in FIG. 17. As theoperator continues to pull the delivery wire 151, the first barb 142passes through the center joint 108, followed by the second barb 146. Asthe operator continues to pull the delivery string 150, the first barbpasses through the proximal joint 106, followed by the second barb 146,as shown in FIGS. 18 and 19. Once the first barb 142 is completelythrough the proximal joint 106, the occluder is in its fully closedposition, and the first catching member 140 can advance no further withrespect to the center joints. As the operator continues to pull on thedelivery string 150, the string detaches from the first barb 142 andpulls the second barb through the proximal joint 106 until the distalstop 147 makes contact against the end cap 148 and the second barb 146passes completely through the proximal joint 106 as shown in FIG. 19.The first barb 142 and the second barb 146 are now longitudinallycoincident, and the combined outside diameter of the two side-by-sidebarbs is greater than the inside diameter of the proximal joint 106,which prevents the barbs from passing back through the proximal joint106 in the distal direction. At this point, and as with a number ofother embodiments, delivery is completed by releasing releasableconnection 153 by unscrewing, opening hooks, or some other process ofdetaching.

FIG. 20 shows an occluder with yet another type of internal interferencecatching mechanism, referred to as an “arrowhead” catch. The catchingmember 160 includes an end cap 162 fixedly attached to the distal joint110, and one or more catching barbs 164 at the proximal end of thecatching member 160. The catching barbs 164 are angled back in thedistal direction, and are flexible to be deformable toward thelongitudinal axis of the catching member 160. A delivery shaft 166attaches to catching member 160 through a releasable connection, such asa claw 167 and a ball 168. The claw 167 grasps a ball 168 (or similarprotrusion) on the catching barbs 164. The releasable connection mayalternatively be implemented by other mechanisms, for example by athreaded end of shaft 166 and threads in catching member 160.

To catch the arrowhead catching mechanism, the operator pulls thedelivery shaft 166 until the proximal side of the device stops againstthe delivery sheath 168. As the operator continues to pull the deliveryshaft, the center joint causes the catching barbs 164 to deform towardthe longitudinal axis of the catching member, allowing the barbs 164 topass through the center joint 108, and subsequently through the proximaljoint 106. Once through the proximal joint 106, the barbs open back totheir original, relaxed position. The shape of the barbs 164 preventsthe catching barbs 164 and catching member 160 from passing back throughthe proximal joint 106, as shown in FIG. 21.

To release the arrowhead catching mechanism, the operator grasps theproximal joint 106 with claws 170 at the distal end of the deliverysheath 168, and pulls the barbs 164 into a recovery sheath 172, as shownin FIG. 22. The outside diameter of the recovery sheath 172 is slightlysmaller than the inside diameter of the proximal joint 106 and thecenter joint 108, so that the recovery sheath 172 can pass through thosecenter joints. Once the barbs 164 are inside the recovery sheath 172,the operator pushes the recovery sheath 172 in a distal direction withrespect to the delivery sheath 168, through the proximal joint 106 andthe center joint 108. The operator then pulls the recovery sheath 172 ina proximal direction while holding the delivery shaft fixed, so that theoccluder and the arrowhead catching mechanism is back in the positionshown in FIG. 20. The operator can then recover and remove the releasedoccluder, or can reposition to redeploy.

FIG. 23 shows an occluder with another embodiment of a catching member180. Catching member 180 includes a proximal catch 182 and a distal stop184. The outside diameter of the proximal catch 182 is greater than theinside diameter of the proximal joint 106 and center joints 108, and thediameter of the distal stop 184 is greater than the diameter of theproximal catch 182. Distal stop 184 is preferably fixedly connected tothe distal joint 110 and thus is not movable with respect to the distalend of the occluder at any time, while the portions of the occluder moveover the proximal end to catch the occluder in place. A ball 186 forconnection to a claw 190 is attached to the proximal catch 182 via astring or suture 188 to form a releasable connection, although asdescribed above, other types of connections can be made.

Referring to FIGS. 24 and 25, to catch the occluder shown in FIG. 23,the operator grasps the ball 186 with the claw 190 attached to adelivery shaft 192, and pulls the delivery shaft 192 until the proximaljoint 106 stops against the delivery sheath 194. As the operatorcontinues to pull the delivery shaft 192, the rounded end of theproximal catch 182 deforms so that the proximal catch 182 can passthrough the center joint 108. The proximal catch subsequently deformsthrough the proximal joint 106 so that the proximal catch can passthrough the proximal joint 106 in the proximal direction. Once theproximal catch 182 passes completely through the proximal joint 106, theproximal joint 106 returns to its original shape, and the flat distalside of the proximal catch 182 prevents the proximal catch 182 frompassing back through the proximal joint 106 in the distal direction, asshown in FIG. 24.

Referring to FIGS. 23 and 24, the catching mechanism 180 may alsoinclude a third catch 196 (shown in broken lines) between the proximalcatch 182 and the distal catch 184. The third catch 196 provides anintermediate stop for engaging the center joint 106. The diameter of thethird catch 196 is approximately equal to the proximal catch 182. Thethird catch 196 allows the distal petals of the occluder to maintaintheir form prior to the engagement of the proximal catch 182, and in theevent the proximal catch 182 fails.

FIG. 25 shows a method for releasing the catching mechanism 180. Theoperator uses claws 198 at the end of the delivery sheath 194 to graspthe proximal joint 106. The operator then uses a recovery shaft 200 topush the proximal catch 182 in a distal direction through the proximaljoint 106 and subsequently through the center joint 108 (not shown).

In another embodiment, FIGS. 26 through 29 show an occluder with aratchet-type catching mechanism, including a catching member 202 with amultiple grooves 204 at its proximal end. The distal end of the catchingmember 202 is fixedly attached to the distal joint 110. A delivery shaft206 attaches to the proximal end of the catching member 202 via a balland claw combination (or other reasonable connection) as described abovefor other embodiments. Other techniques for attaching the delivery shaft206 (or other delivery means such as a delivery string) may also beused. The proximal joint 106 includes a pair of teeth 210, extendingfrom the proximal side of the proximal joint 106, for engaging thegrooves 204 on the catching member 202.

Referring to FIG. 27, the operator catches the occluder by pulling onthe delivery shaft 206 until the pair of teeth 210 of the proximal joint106 stop against the delivery sheath 208, then continuing to pull on thedelivery shaft until the teeth 210 engage the first of the grooves 204.As the operator continues to pull the delivery shaft 208, the teeth 210pass over the grooves by extending away from the longitudinal axis asshown in FIG. 28. The grooves function as inclined planes or ramps toforce the teeth away from the longitudinal axis as the operator pullsthe delivery shaft 208. When the operator stops pulling on the deliveryshaft 208, the teeth 210 settle into the grooves, preventing thecatching member 202 from further movement.

The grooves 204 may be set at equal angles, as shown in FIGS. 26 through28, or one side may be more steeply angled to resist motion more in oneparticular direction. For example, FIG. 29 shows grooves 204 with oneside of each groove angled, and the facing side nearly perpendicular tothe longitudinal axis of the catching member 202 a. Note that thecatching mechanism in FIG. 29 includes grooves on only one side of thecatching member 202 a. Further, only one tooth 212 extends from theproximal joint for engaging the grooves in the catching member 202 a ofFIG. 29.

The operator can release the catching member 202 by pushing on thecatching member 202 with a recovery shaft or other similar mechanism sothat the teeth 210 extend away from the longitudinal axis of thecatching member 202 as the teeth 210 pass over the grooves 204.

FIG. 30 shows another embodiment of an interference catching mechanism,including a catching member 220 having a longitudinal split 222 andprotrusions 224 extending in a radial direction away from thelongitudinal axis of the catching member 220. The distal end of thecatching member 220 is fixedly attached to the distal joint 110. Theproximal joint 106 includes apertures 226 for engaging the protrusions224 when the catching mechanism is in the caught position. In order tocatch the catching mechanism, the operator pulls the catching member 220in a proximal direction via a delivery wire 228 (or a delivery shaft orother similar delivery mechanism). In the embodiment shown in FIG. 30,the delivery wire 228 attaches via bendable hooks 230 to an eyelet 232that is secured to the catching member 220. As with other embodimentsdescribed herein, alternative techniques for attaching a deliverymechanism to the catching mechanism 220 may also be used (for example,direct attachment or a ball/claw arrangement).

As the operator pulls the delivery wire 228 in a proximal direction, thesplit 222 allows the protrusions 224 to deflect toward the longitudinalaxis of the catching member 220, so that the catching member 220 canpass through the center joint 108. As the operator continues to pull thedelivery wire 228, the protrusions 224 again deflect toward thelongitudinal axis of the catching member 220 until the protrusions 224align with the apertures 226, as shown in FIG. 31. At this point, theprotrusions 224 spring back to their relaxed position and engage theapertures 226 to catch the catching mechanism. Alternatively, ratherthan using apertures 226, the protrusions can be pulled all the waythrough proximal joint 106, such that they are against the proximal endof the proximal joint. In either case, the delivery wire would bedetached to complete the delivery.

FIGS. 32 and 33 show an occluder with another embodiment of a catchingmechanism that includes a catching member 230 with its distal endfixedly attached via an end cap 231 to the distal joint 110 and has aproximal end 232 that can be made to form a hook 234 when deployed andin a caught position, as shown in FIG. 33. In one embodiment, thecatching member 230 is made of a spring material known in the art, andis normally in a hooked configuration. To deploy an occluder with such acatching mechanism, the operator straightens the hook 234 and insertsthe catching member 230 in a delivery tube that keeps the hook in arelatively straight position. The delivery tube keeps the hook 234straight while the operator deploys the occluder, at which time theoperator withdraws the delivery tube in a proximal direction, releasingthe hook 234 to the position shown in FIG. 33.

In another embodiment, the proximal end 232 of the catching member 230is made from a shape memory material (e.g., nitinol wire) that isdesigned to form hooked ends when deployed in a caught position. Whiledeploying the occluder, the proximal end 232 of the catching member 230is in its martensitic form. Once the occluder is fully deployed, theproximal end of the catching member 230 reverts to austenite to form thehooked end 234 and engage the proximal joint 106 as shown in FIG. 33.

A next group of embodiments includes external interference catches inwhich catching members pass outside of the center joints along alongitudinal axis, and engage the center joints from the outside ratherthan from the inside as in the embodiments above.

FIG. 34 through 37 show an occluder with one type of externalinterference catching mechanism, including a first catching member 240and a second catching member 242, both fixedly attached to the distaljoint 110 and both having anchor barbs 244 at their proximal ends. Tocatch this type of catching mechanism, the operator pulls the distaljoint 110 toward the proximal joint 106 (using one of several techniquesdescribed herein), causing the anchor barbs 244 to pass over the centerjoint 108 and subsequently the proximal joint 106. The anchor barbs 244engage the proximal end of the proximal joint 106 as shown in FIG. 35,thereby catching the occluder. Note that in devices such as that shownin FIG. 1b , there can be gaps between the places where petals areconnected to joints.

FIGS. 36 and 37 show another embodiment of a catching mechanism,including a first catching member 246 and a second catching member 248,both fixedly attached to the distal joint 110 and both having a firstset of anchor barbs 250 at their proximal ends. The catching mechanismfurther includes a third catching member 252 and a fourth catchingmember 254, both fixedly attached to the central joint 108 and bothhaving a second set of anchor barbs 256 at their proximal ends. To catchthis type of catching mechanism, the operator pulls the distal joint 110toward the proximal joint 106 (using one of several techniques describedherein), causing the first set of anchor barbs 250 to pass over thecenter joint 108, while the second set of anchor barbs 256 pass over theproximal joint 106. As a result, the first set of anchor barbs 250engage the center joint 108, and the second set of anchor barbs 256engage the proximal joint 106, as shown in FIG. 37.

The following embodiments are referred to as stick anchor catches, andinclude occluder catching mechanisms with a rigid stick portion thatrotates from an orientation substantially parallel to the longitudinalaxis of the occluder to an orientation that is substantiallyperpendicular to the longitudinal axis of the occluder. While parallelto the longitudinal axis, the stick portion passes through the occludercenter joint. When the stick portion rotates into a position that isperpendicular to the longitudinal axis of the occluder, the stickportion cannot pass through the center joint because the length of thestick portion is greater than the inside diameter of the center joint.While preferably parallel and perpendicular, any configuration can beused that moves a potential stopper from a first position for allowingthe stick to pass through an opening, to a second position not allowingthe stick to pass through.

FIGS. 38 through 40 show one embodiment of a stick anchor catch,including an elastic string 260 (or suture) having its distal endfixedly attached to the distal joint 110 and its proximal end pivotallyattached to an anchor stick 262. The anchor stick 262 has a crosssection that is smaller than the inside diameter of the occluder centerjoints, and preferably has a slight bend in one end 266 to make iteasier to catch. A delivery string 264 attaches releasably to an end 268of the anchor stick 262.

Referring also to FIGS. 39 and 40, when the operator pulls the deliverystring in a proximal direction with respect to the occluder, the anchorstick 262 shifts to an orientation that is substantially parallel to thelongitudinal axis of the occluder. In this orientation, the anchor stick262 easily passes through the center joint 108 and the proximal joint106. Once the anchor stick is completely through the proximal joint 106,the elastic string 260 is in tension. As the operator moves the deliverystring 264 in the distal direction, the bend in the end 266 of theanchor stick 262 bumps against the proximal end of the proximal joint106, and the anchor stick 262 pivots about the point where the bendcontacts the proximal joint 106 until the anchor stick is perpendicularto the longitudinal axis of the occluder. The proximal joint 106 in FIG.39 includes a slot 270 into which the anchor stick 262 fits when thecatching mechanism is in the caught position. Other embodiments may notinclude the slot 270, or the slot can be more V-shaped with the outerend much wider than the width at the interior of the joint 106. Thetension in the elastic string 260 maintains the catching mechanism inthe caught position by holding the anchor stick 262 against the proximalend of the proximal joint 106.

The bend in the anchor stick may alternatively be pointing toward thecenter joint 106, as shown in FIG. 41, to provide for better septalprofile. In yet another embodiment, both ends of the anchor stick mayinclude a bend, a shown in FIG. 42, forming a generally U-shapedconfiguration.

The next group of embodiments relate to what are termed here “puzzlecatches.” They include components that mate in the caught position,typically with a friction snap-fit or friction press-fit.

FIGS. 43 and 44 show one embodiment of a puzzle catching mechanism foroccluders. In this embodiment, a catching member 280 has a first loop282 at a first end, and a second loop 284 at a second end. The firstloop 282 and the second loop 284 are oriented at an angle, andpreferably substantially orthogonally with respect to one another. Otherembodiments may include different orientations. The middle connectingportion 285 of the catching member 280 (i.e., between the two loops) isfixedly attached to the center joint 108. The proximal side of thedistal joint 110 includes a first slot 286 oriented and shaped toprovide a press-fit for the first loop 282. The distal side of theproximal joint 106 includes a second slot 288 oriented and shaped toprovide a press-fit for the second loop 284. In each case, the slot hasa smaller width at the outside and a longer internal diameter to allow asnap fit. To catch this puzzle catching mechanism, the operator movesthe distal joint 110 in a proximal direction with respect to theproximal joint 106 until the first loop 282 engages the first slot 286,and the second loop 284 engages the second slot 288. These loops forceopen the outer part of the slots and then snap in the slot, therebycatching the occluder as shown in FIG. 44.

The catching member 280 of FIGS. 43 and 44 may include an aperturerunning through it along a longitudinal axis of the catching member 280to allow a delivery string (or wire or shaft) to pass from the proximalend of the occluder to the distal end of the occluder. The deliverystring is fixedly attached to the distal joint. To catch the occluder,the operator pulls the delivery string in a proximal direction. Theproximal joint stops against a delivery sheath, and as the operatorcontinues to pull on the delivery string, the distal joint moves in adistal direction toward the proximal joint until the occluder catches inthe closed position.

FIGS. 45 and 46 show another embodiment of a puzzle catching mechanismfor occluders. This embodiment has press-fit slots 290 on the proximaljoint 106, shaped and oriented to facilitate press-fit mating with theoccluder petals 292 on the proximal side of the center joint 108. Thisembodiment also has press-fit slots 294 on the proximal side of thedistal joint, shaped and oriented to facilitate press-fit mating withthe occluder petals 296 on the distal side of the center joint 108. Theoperator catches this catching mechanism by moving the distal joint 110in a proximal direction relative to the proximal joint 106 until thepress-fit slots 290 mate with the occluder petals 292, and the press fitslots 294 mate with the occluder petals 296, as shown in FIG. 46.

The catching mechanism shown in FIGS. 45 and 46 also includes apress-fit slot 298 on the proximal side of the center joint 108, and apress-fit slot 300 on the distal side of the center joint 108, formating with the occluder petals on the proximal joint 106 and the distaljoint 110, respectively. These slots and their corresponding occluderpetals mate at the same time the slots 290, 294 engage as describedabove. Other embodiments may include only the press-fit slots 290 and294 on the proximal joints and the distal joint, respectively, asdescribed above.

FIGS. 47 and 48 illustrate a variation of the puzzle catching mechanismshown in FIGS. 45 and 46. In FIG. 47, the distal joint 110 includesball-ended protrusions 310 that mate with corresponding slots 312 on thedistal end of the center joint 108. Likewise, the proximal joint 106includes ball ended protrusions 314 that mate with corresponding slots316 on the proximal end of the proximal end of the center joint 108. Tocatch the puzzle catching mechanism of FIG. 47, the operator moves thedistal joint 110 in a proximal direction with respect to the proximaljoint 106 until the ball ended protrusions mate with their correspondingslots, thereby catching the occluder, as shown in FIG. 48.

Other embodiments of the catching mechanism shown in FIG. 47 may reversethe position of the ball-ended protrusion/slot combinations, i.e., havethe protrusions on the center joint, and the slots on the proximal jointand the distal joint. Various combinations of these embodiments may alsobe used, i.e., the center joint 108 may have some combination ofprotrusions and slots.

FIG. 49 shows a puzzle catching mechanism with a first catching member320 having a proximal end 322 fixedly attached to the proximal joint106, and a loop 324 at the distal end. The catching mechanism alsoincludes a second catching member 326 having a distal end 328 fixedlyattached to the distal joint 110, and a C-shaped clamp 330 at theproximal end. The occluder petals are not shown for clarity. The centerjoint is shaped as shown in FIG. 49 to allow the clamp 330 to engage theloop 324 at the center joint 108 via a friction fit when the catchingmechanism is deployed. While FIG. 49 shows the ends of clamp 330 with agap, they would likely be very close together or may even be essentiallyin contact with each other and spread on contact with loop 324.

FIGS. 50 and 51 show a puzzle catching mechanism in which the occluderpetal members 340 are arranged so as to overlap and interlock oneanother, thereby catching the occluder. FIG. 50 shows the proximal joint106 and the center joint 108 in an released position. When the centerjoint 108 and the proximal joint 106 are brought together, petals 340 aof the center joint 108 pass beyond and overlap the petals 340 b of theproximal joint 106 so as to be on the proximal side of the petals 340 bof the proximal joint 106, as shown in FIG. 51. Thisoverlapping/interlocking of the petals prevents movement of the centerjoint 108 away from the proximal joint 106 in a distal direction,thereby catching the occluder. The distal joint (not shown) and thecenter joint similarly have petals arranged to overlap/interlock oneanother to catch the center joint and distal joint together.

The next embodiments relate to catches within the occlusion members,including adhesive or other securing material as part of the occluderstructure.

FIGS. 52 and 53 illustrate an adhesive catching mechanism where theoccluder petals 350 are covered with a tissue scaffold. The innersurfaces 352 of the tissue scaffold (i.e., the surfaces facing oneanother between the proximal joint 106 and the center joint 108, andbetween the center joint 108 and the distal joint 110) are coated withan adhesive material. Once the operator deploys the occluder in the PFOdefect, the operator injects an activating material into the occluder toactivate the adhesive, thereby allowing surfaces 352 a to adhere tosurfaces 352 b, and surfaces 352 c to adhere to surfaces 352 d, as shownin FIG. 53.

FIG. 54 shows a catching mechanism similar to the one shown in FIGS. 52and 53, but instead using an adhesive to catch the occluder, a hook andloop material (i.e., a “velcro” type fabric) is secured to the innersurfaces of the tissue scaffold. When the occluder is deployed, theinner surfaces having complementary sets of hooks and loops cometogether and the hooks latch onto the loops, thereby securing the innersurfaces together. In FIG. 54, the surfaces facing the distal end of theoccluder have an array of hooks, and the surfaces facing the proximalend of the occluder have an array of loops. In other embodiments, theopposite arrangement may be used, or some combination thereof, as longas the facing surfaces that are to be secured to one another havecomplementary sets of hooks/loops. Other connecting arrangements can beused, such as appropriate hooks on each side for a hook-on-hookconnection.

FIG. 55 shows a catching mechanism similar to the one shown in FIG. 54,except that ball and loop latching materials are disposed on the innersurfaces of the tissue scaffold rather than hook and loop materials.Other embodiments may includes similar “latching” fabrics or materialsto secure facing tissue scaffold surfaces to catch the occluder.

The following embodiments include “two-element” catches and coilcatches. The two-elements catches operate on the principle that twoelements work together such that either one is small enough to passthrough an occluder center joint, but the two elements together form aunit that is too big to pass through an occluder center joint. A coilcatching mechanism uses a catching member made from a material that,when relaxed, assumes a coil shape such as a helical spring with anoutside diameter larger than the inside diameter of the occluder centerjoints. This catching member can be stretched along its longitudinalaxis during occluder deployment, so that its outside diameter is smallerthan the inside diameter of the center joints.

FIGS. 56 and 57 show one type of two elements catch, including multiplepairs of balls distributed along a pair of strings. In FIG. 56, a firstball 360 and a second ball 362 are fixedly attached to a first string364 (or wire or suture). The distal end of the first string 364 isreleasably attached to a ball 365 that is part of the distal joint 110,either held to the distal end by the tension, or fixedly connected tothe distal end. The proximal end of the first string 364 extends outthrough the center joint 108 and the proximal joint 106 to the operator.A third ball 366 and a fourth ball 368 are fixedly attached to a secondstring 370. The distal end of the second string 370 is releasablyattached to the ball 365 at the distal joint 110, and the proximal endof the second string 370 extends out through the center joint 108 andthe proximal joint 106 to the operator. The length of the first string364 from the first ball 260 to the distal joint is the same as thelength of the second string 370 from the third ball 366 to the distaljoint 110. The length of the first string between the first ball 360 andthe second ball 362 is the same as the length of the second string 370from the third ball 366 to the fourth ball 368. These lengths ensurethat the first ball 360 and third ball 366 will be side by side (i.e.,at the same point) along the longitudinal axis of the occluder, and thesecond ball 362 and the fourth ball 368 will be side by side along thelongitudinal axis of the occluder. At least one of the strings can beelastic, in this case string 364, so that one of the strings may bestretched to stagger the balls along the longitudinal axis, as shown inFIG. 56. Each of the strings 364 and 370 can include multiple stringsegments. In each case, the strings can be fixedly connected to therespective balls if a mechanism is provided to cut the strings afterdelivery.

To deploy the occluder, the operator pulls one of the strings in aproximal direction to stagger the first and third balls, and the secondand fourth balls. While the balls are staggered, the operator pulls bothstrings until the first ball 360 and the third ball 366 are on theproximal side of the center joint 108, and the second ball 362 and thefourth ball 368 are on the proximal side of the proximal joint 106. Theoperator then releases the string that is in elastic tension, so as toreturn the first/third and the second/fourth ball pairs in theside-by-side configuration. When the first/third ball and thesecond/fourth pairs are in side-by-side configuration, as shown in FIG.57, the pairs cannot pass through the center joints, thereby catchingthe occluder. The strings are then detached or cut from the device tocomplete delivery.

To release the occluder before the delivery strings are detached, theoperator pulls on one of the strings to once again stagger the balls,thereby allowing the staggered balls to pass through the center joints.

Other embodiments may stagger the balls via other techniques. Forexample, the first string 364 and second string 370 may be onecontinuous string that passes through the distal joint and can slidealong a fixed or rotatable axle, so that the distal joint 110 acts as apulley. The operator pulls on one of the strings to stagger or realignthe ball pairs.

FIGS. 58 and 59 show yet another two element catching mechanism for anoccluder. A first ball 380 and a second ball 382 are fixedly attached toa string 384 (or wire, suture, or tube). The distal end of the string384 is fixedly attached to a ball 385 that forms part of the distaljoint 110, and the proximal end of the string 384 passes through thecenter joint 108 and the proximal joint 106 and out to the operator. Todeploy the occluder, the operator pulls the string 384 until theoccluder stops against a delivery sheath 386. The operator continues topull the string 384 until the first ball 380 is on the proximal side ofthe center joint 108 and the second ball 382 is on the proximal side ofthe proximal joint 106. The operator then inserts a catching rod 388through the proximal joint 106, the center joint 108, and the distaljoint 110, as shown in FIG. 59. The outside diameter of the catching rod388 is large enough to prevent either ball from passing through a centerjoint while the catching rod 388 is disposed within the center joints asshown in FIG. 59. Note that the string 384 may include multiple stringsegments. The method of using claws, as referred to in conjunction withFIGS. 13-15, could also be used here to recover the device.

FIGS. 60 and 61 illustrate another embodiment similar to that shown inFIGS. 58 and 59. A catching tube 389 with an outside diameter slightlysmaller than the inside diameter of the center joints includes twoapertures in the side wall, each large enough for a first ball 390 or asecond ball 391 to pass. A string 392 attaches the first ball 390 to thesecond ball 392. The operator deploys the occluder within the PFO bymoving the distal joint 110 toward the proximal joint 106, using any oneof several delivery techniques described herein or known in the art. Theoperator then inserts the catching rod 393, thereby retaining each ballin its respective aperture. At least a portion of each ball extendbeyond the outside diameter of the catching tube 389 in this position,preventing the proximal joint 106 from moving in the proximal directionor the distal joint from moving in the distal direction, therebycatching the occluder.

FIGS. 62 and 63 illustrate an example of a coil catch. In thisembodiment, the coil catching member 394 is stretched along a deliveryrod 396, so that the outside diameter of the stretched coil is less thanthe inside diameter of the occluder center joints. The operator deploysthe occluder within the PFO by moving the distal joint 110 toward theproximal joint 106, using any one of several delivery techniquesdescribed herein or known in the art. Once the occluder is deployed, theoperator releases the coil catching member 394, and portions of thecatching member 394 that are not restrained by the inside diameter ofthe center joints expand, as shown in FIG. 63, thereby catching theoccluder. The coil at the distal end can be rigidly attached to thedistal joint 110 from the beginning, or it can be held in place withspring forces without a rigid connection.

The following group of embodiments relate to end cap catches thatinclude an end cap that fixedly attaches to one or both ends of theoccluder and engage a catching member to hold the occluder in a caught,deployed position.

FIGS. 64-66 show an embodiment of an end cap catching mechanism,including a catching member 400 with a catching ball 402 fixedlyattached to its proximal end, and its distal end fixedly attached to thedistal joint 110. This embodiment shows the distal end of the catchingmember 400 fixedly attached to a ball 405 having an outside diameterlarger than the inside diameter of the distal joint 110, although othertechniques of securing the distal end of the catching member 400 to thedistal joint may also be used. The outside diameter of the catching ball402 may be slightly less than the inside diameter of the center joint108 and the proximal joint 106. A detachable delivery wire 404 (ordelivery shaft) attaches to the catching ball 402, and a catching cap406 is disposed about the delivery wire 404 on the proximal side of thecatching ball 402.

The operator catches this catching mechanism by pulling on the deliverywire 404 so as to pull the distal joint 110 in a proximal directiontoward the proximal joint 106. Once the catching ball 402 is on theproximal side of the proximal joint 106, as shown in FIG. 65, theoperator pushes the catching cap 406 over the catching ball 402. Inorder to pass through the catching cap 406 in the proximal direction,the catching ball 402 deforms catching cap 406, expanding the insidediameter of the catching cap 406. Once the catching ball is through thecatching cap 406, the catching cap 406 returns to its original shape,resisting the catching ball 402 from passing back through the catchingcap 406 in a distal direction. The delivery wire 404 is then detachedfrom ball 402 if releasably attached to it, or is cut to sever theconnection to ball 402.

In one embodiment, the catching cap has threads on its distal side, sothat the catching cap 406 can be screwed onto mating threads disposed onthe outside of the proximal portion of the proximal joint 106. In otherembodiments, a claw can be used to grip the ball 402.

The following embodiments relate to other catches that do not fall inthe previous categories of catches.

FIGS. 67 and 68 show a catching mechanism with an end cap 410 fixedlyattached to the distal side of the distal joint 110, and a proximaljoint with two apertures 412 and 414 in its side walls. The end cap 410also includes two apertures 416 and 418. A continuous string or wire 420passes through the first aperture 412, through the proximal joint 106,the center joint 108 and the distal joint 110, then out through the endcap aperture 416. The wire 420 loops back through the other end capaperture 418, through the distal joint 110, the center joint and theproximal joint and out through the second proximal joint aperture 414.

The two ends of the wire are secured together with an anchor block 422on the proximal side of the proximal joint 106, and both ends continueon to the operator through a delivery sheath (not shown). To catch thedevice, the operator twists the two ends of the wire at the proximalside of the proximal joint 106 by rotating the anchor block 422.Twisting the wire effectively shortens the wire within the occluder,drawing the distal joint 110 and the proximal joint 106 together. Oncethe operator has twisted the wire ends enough to close the occluder, theoperator severs both ends of the wire at the distal side of the anchorblock 422, as shown in FIG. 68. The remaining twisted bundle 424 of wirekeeps the occluder in a closed and caught position.

FIGS. 69 and 70 show a catching mechanism with a catching member 430that includes a double anchor end catch 432 at one or both ends. The endcatch 432 includes two or more branches 434 extending out and curvingaway from the occluder longitudinal axis. These branches can be held tojoint 110 by forces without a rigid connection, or with a rigidconnection. The end catches 432 are preferably made of a metallicmaterial characterized by a spring constant, so that the branches 434can be extended and held to be substantially parallel to the occluderlongitudinal axis when deploying the occluder. Once the occluder isdeployed, the operator releases the branches 434 so that they return totheir original curved orientation, as shown in FIG. 70. Duringdeployment, the operator can hold the branches in the extended position(i.e., substantially parallel to the occluder longitudinal axis) inseveral ways, including by pulling them straight with a set of deliverywires, as shown in FIG. 69, or by restraining them in an open positionwith a delivery catheter, or via other similar techniques known in theart.

Each of the branches may also include spring loops along its length toprovide more resistance to straightening the branches 434 whendelivering the occluder, so that they more easily return to theiroriginal curved orientation once the occluder is deployed.

In the embodiments described above, the details of the portions of thedevice that would contact septum primum and septum secundum have beenshown primarily in a general manner, except for certain figures such asFIG. 1b . The device can have a shape of the type shown in FIG. 1b , orone of the variations shown in the incorporated patent applications. Inaddition, other types of petals, loops, struts, or other pieces forproviding some compressive force sufficient to hold together septumprimum and septum secundum to substantially prevent a clot from passingfrom the right atrial side to the left atrial side. In addition, thecatching mechanisms that are described here can be used with other typesof devices, such as those for closing an atrial septal defect (ASD).

In the embodiment of FIG. 1b , the loops or petals are formed byextending away from one joint and looping around to be connected to theother joint, such that the petal extending away from one joint andextending away from the other joint are offset by some angle, such as90° as shown in FIG. 1b . As indicated above, other numbers of loops andpetals can be used, and they can have other configurations including asloops that define a plane substantially perpendicular to the PFO tunnelrather than substantially parallel to it as shown in FIG. 1c . The sidesof the device can be different both in size and/or in type; e.g., thedistal side petals could be larger or smaller than proximal side petals,or one side could have closed loops and the other side could have strutsthat do not loop.

The embodiments described here are described preferably for use with adevice made of a polymer and formed from a single tube, such that thetube is a single monolithic material. The catching mechanism can be allor partly monolithic or integral with the tubular structure, or therecan be an absence of any type of bonding or rigid connection to the restof the tubular structure, in which case there may be some spring forceor other force that holds the catching mechanism in place. While thedevice is thus shown as being substantially formed from a single tubularbody, the catching mechanism as described in the embodiments above couldbe used with other types of devices, including those formed from manypieces, and including devices formed from other materials, includingstainless steel or nitinol.

In cases in which the device is made of a polymer, it can be desirableto add an additive or coating to the material to make it radiopaque tomake it more visible in a wider variety of imaging techniques.

While the description above refers to strings and wires, and while theterm “wire” might convey a more rigid piece than a string, the two termsare essentially interchangeable, and further include embodiments inwhich the wire or string is a hollow tube or conduit to allow anotherwire, as needed, to pass through its longitudinal axis.

Having described many embodiments, it should be apparent themodifications can be made without departing from the scope of thepresent invention.

What is claimed is:
 1. A device for occluding a septal defect that has adistal side and a proximal side, the device comprising: a distal endhaving a distal opening and a distal portion for contacting the distalside, the distal portion including a plurality of petals; a proximal endhaving a proximal opening and a proximal portion for contacting theproximal side, the proximal portion including a plurality of petals; acenter portion for extending through the septal defect, and; a coilextending through the proximal opening of the device and through thedistal opening of the device such that portions of the coil extenddistal of the distal end and proximal of the proximal end in apre-deployed configuration and a deployed configuration.
 2. The deviceof claim 1, wherein the device is adapted to close a patent foramenovale (PFO).
 3. The device of claim 1, wherein the coil being configuredto maintain the proximal portion and the distal portion in the deployedconfiguration.
 4. The device of claim 3, wherein the coil beingconfigured to maintain the proximal portion and the distal portion inthe deployed configuration in response to release from a deliverysystem.
 5. The device of claim 4, wherein the portions of the coilextend distal of the distal end and proximal of the proximal end catchthe distal end and the proximal end in response to release from thedelivery system.
 6. The device of claim 1, wherein the proximal portionand the distal portion each include a first area in the pre-deployedconfiguration and a second area in the deployed configuration, and thesecond area is less than the first area.